Cancer remains one of the scourges of mankind and radiation therapy is one of the chief tools to combat same. In radiation therapy a high energy treatment radiation beam is used to destroy cancerous tissue whilst sparing healthy one.
A particular type of radiation therapy planning called Intensity Modulated Radiotherapy (IMRT) allows spatially modulating a treatment beam to precisely conform not only in shape but also in terms of prescribed dosage requirements as per a treatment plan.
Standard IMRT implementations do not take into account the eventuality that the anatomy of the treated site may change throughout the course of radiation delivery.
Although in the past some more advanced schemes have been proposed on how to adapt treatment plans to changes in the treated anatomy, the decision on when to adapt still rests with the oncologist. See for instance Q Jackie Wu et al, “On-line re-optimization of prostate IMRT plans for adaptive radiation therapy”, Phys. Med. Biol. 53 (2008) 673-691.
But still, in existing schemes, no clues are provided to the human professional on when and/or under what conditions a treatment plan should be re-optimized. The information available to medical personal to reach such a decision may be overwhelming and it may be difficult to draw definite conclusion on how to proceed. This problem is further compounded by the limited resources available to national health services as plan adaptions may prove expensive.